Freeze cleaning

Flush inlet headers, laterals, and return lines Drain to prevent freezing Clean tower basin Adjust tower fans Service Air... 

Pressure test piping and equipment Flush and clean piping and equipment Drain water to prevent freezing Blow out piping Continuity testing with air... 

Most vessels can now freeze their catch at sea, enabling them to stay offshore without the need to run back to a port within the limited life of the chilled product. If the fish is to be cleaned and processed later, it is frozen whole, either by air blast or, more usually, in vertical plate freezers (see Figure 1.9b), followed by frozen storage. Some fishing vessels and the fish factory vessels will carryout cleaning, filleting and other operations on board and then freeze and store the final product. 

A solution of sodium ethylate is prepared from 60 g. (2.6 gram atoms) of clean sodium and 700 cc. of absolute alcohol (Note 1) in a 2-1. round-bottomed flask, equipped with a reflux condenser. To the hot solution is added a mixture of 234 g. (2 moles) of pure benzyl cyanide (Note 2) and 264 g. (3 moles) of dry ethyl acetate (Note 3). The mixture is thoroughly shaken, the condenser closed with a calcium chloride tube, and the solution heated on the steam bath for two hours before standing overnight (Note 4). The next morning the mixture is stirred with a wooden rod to break lumps, cooled in a freezing mixture to — io°, and kept at this temperature for two hours. The sodium salt is collected on a 6-in. Buchner funnel and washed four times on the funnel with 250-cc. portions of ether. The filter cake is practically colorless and corresponds to 250-275 g. of dry sodium salt, or 69-76 per cent of the calculated amount. The combined filtrates are placed in the freezing mixture until they can be worked up as indicated below. 

All production processes, such as ampoule washing and sterilization, solution filtration, equipment set-up and operation, sorting, and freeze-drier cleaning and operation, should be covered in detail in a procedure manual to ensure that all operations are understood as well as carried out properly and uniformly. Cleaning, sterilization, sterile filtration, filling, and aseptic processing operations must be validated. 

Another application is to combine ice production and water purification since impurities are pressed out as water freezes. It is possible to freeze sea water or polluted ground water and use the cleaned melt water for both cooling and drinking. In Greenport, New York, sea water was cleaned from 3.0% to 0.00005% by freezing (Taylor, 1985). 

The dry ice blaster is an effective and mess-free method for in-place cleaning that eliminates the need to disassemble machinery before it is cleaned. Compressed air propels tiny dry ice pellets at supersonic speeds so they flash freeze and then lift grime, paint, rust, mold, and other contaminants from metal surfaces. Pellets vaporize quickly into the air, leaving no wastewater or solvents, only the soiled contaminant to be swept up. 

To evolve H2 for measurement of D/H burn 5 mg dry sawdust in 1 atm. 02 in a cupric oxide furnace at 750 °C. Use oxygen purified over silica gel and cupric oxide to ensure that the 02 is hydrogen free. Freeze out H20 and C02 in a liquid oxygen trap. Release C02 at dry ice temperature. React H20 vapor on clean uranium shavings at 950 °C, thus producing H2 quantitatively. 

A typical grinding and sieving system (Fig. 2.5) produces dust which has to be collected. If in addition a CIP (cleaning in place) installation is installed, the total preparation equipment becomes a major part of the whole freezing and freeze drying installation. Figure 2.6 shows only the collecting container for the dust, which is sorted by size while below the container is the vibration transport system. 

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